fix(room): load reactions for IDB-cached messages via WS-first fallback

- thisLoadReactions helper: batch-fetches reactions for loaded messages
  via WS (RoomWsClient.request() does WS-first → HTTP fallback automatically)
- Called after both IDB paths (initial load + loadMore) so reactions are
  populated even when messages come from IndexedDB cache
- Also deduplicated API-path reaction loading to use the same helper

src/contexts/room-context.tsx

@@ -260,6 +260,40 @@ export function RoomProvider({
     };
   }, [activeRoomId, wsClient]);
 
+  /**
+   * Fetch reactions for a batch of messages via WS (with HTTP fallback),
+   * then merge them into the messages state.  Fires-and-forgets so it
+   * does not block the caller.
+   */
+  const thisLoadReactions = (
+    roomId: string,
+    client: NonNullable<ReturnType<typeof wsClientRef.current>>,
+    msgs: MessageWithMeta[],
+  ) => {
+    const msgIds = msgs.map((m) => m.id);
+    if (msgIds.length === 0) return;
+    client
+      .reactionListBatch(roomId, msgIds)
+      .then((reactionResults) => {
+        const reactionMap = new Map<string, import('@/lib/room-ws-client').ReactionItem[]>();
+        for (const result of reactionResults) {
+          if (result.reactions.length > 0) {
+            reactionMap.set(result.message_id, result.reactions);
+          }
+        }
+        if (reactionMap.size > 0) {
+          setMessages((prev) =>
+            prev.map((m) =>
+              reactionMap.has(m.id) ? { ...m, reactions: reactionMap.get(m.id) } : m,
+            ),
+          );
+        }
+      })
+      .catch(() => {
+        // Non-fatal: WS push will keep reactions up to date
+      });
+  };
+
   const loadMore = useCallback(
     async (cursor?: number | null) => {
       const client = wsClientRef.current;
@@ -284,7 +318,9 @@ export function RoomProvider({
             const minSeq = cached[0].seq;
             setNextCursor(minSeq > 0 ? minSeq - 1 : null);
             setIsLoadingMore(false);
-            // No API call needed — WS will push any new messages that arrived while away
+            // No API call needed — WS will push any new messages that arrived while away.
+            // Fetch reactions via WS (with HTTP fallback) so reactions appear without extra latency.
+            thisLoadReactions(activeRoomId, client, cached);
             return;
           }
         }
@@ -310,6 +346,8 @@ export function RoomProvider({
               setIsHistoryLoaded(true);
             }
             setIsLoadingMore(false);
+            // Also fetch reactions for the IDB-loaded history messages.
+            thisLoadReactions(activeRoomId, client, idbMessages);
             return;
           }
           // IDB empty for this range — fall through to API
@@ -355,28 +393,8 @@ export function RoomProvider({
         }
         setNextCursor(resp.messages.length > 0 ? resp.messages[resp.messages.length - 1].seq : null);
 
-        // Fetch reactions for all loaded messages
+        // Fetch reactions for all loaded messages (WS-first with HTTP fallback)
-        const msgIds = newMessages.map((m) => m.id);
+        thisLoadReactions(activeRoomId, client, newMessages);
-        if (msgIds.length > 0) {
-          try {
-            const reactionResults = await client.reactionListBatch(activeRoomId, msgIds);
-            const reactionMap = new Map<string, import('@/lib/room-ws-client').ReactionItem[]>();
-            for (const result of reactionResults) {
-              if (result.reactions.length > 0) {
-                reactionMap.set(result.message_id, result.reactions);
-              }
-            }
-            if (reactionMap.size > 0) {
-              setMessages((prev) =>
-                prev.map((m) =>
-                  reactionMap.has(m.id) ? { ...m, reactions: reactionMap.get(m.id) } : m,
-                ),
-              );
-            }
-          } catch {
-            // Reactions will be loaded via WebSocket updates if backend supports it
-          }
-        }
       } catch (error) {
         if (abortController.signal.aborted) return;
         handleRoomError('Load messages', error);